Design and Construction of an Actively Frequency-Switchable RF Coil for Fast Field-Cycling Magnetisation Transfer Contrast MRI

Chang-Hoon Choi¹, Ioannis Lavdas¹, James M. S. Hutchison¹, David J. Lurie¹

An off-resonance RF pre-saturation pulse is typically employed for magnetisation transfer contrast MRI. Measuring the magnetisation transfer (MT) effect as a function of magnetic field (B₀) may provide valuable. In order to conduct field-dependent MT experiments, two techniques are required. Firstly, B₀ should be switched between levels by fast field-cycling during irradiation of the saturation pulse, and secondly the resonance frequency of the resonator (f₀) should also be shifted simultaneously. Here, we constructed the frequency-switchable RF coil using PIN diodes. (f₀) is actively switched between five different values, with excellent impendent matching (about -40dB) and the Q-factor (approximately 80).